Abstract
In this paper, the width and length of a hydraulic fracture are estimated from the analysis of wave propagation from an active to an offset well. The method is based on a Krauklis wave model, which describes acoustic waves, propagating in a narrow layer, filled with a viscous fluid and surrounded by a poroelastic formation. Attenuation depends highly on the width of the channel, formation parameters, and the frequency of a wave. That is why the wave's attenuation during propagation from an active to an offset well allows estimating the fracture's geometry.
Obtained estimations are compared with numerical simulations of an opening fracture using real pumping data. The geometry of the fracture, calculated with a 3D fracture simulator, is in a reasonable agreement with width and length estimated analytically by analyzing the attenuation of Krauklis waves.
The comparison of numerical and analytical reasoning is also used for the estimation of the number of active clusters per stage. Another attempt to estimate the number of fractures per stage was made by analyzing the compression of formation and pressure growth on the offset well. Analysis of acoustic waves also allows characterizing the type of multiwell communications and to trace possible fluid migration.
The suggested method of processing Krauklis waves detects fracture hits and stress shadows by analyzing pressure record and can be applied in the field to refine pumping design of future stages to prevent leakoff. After some experimental validation, this method can also be used for evaluation of the number of effective fractures per stage.
